In conventional barbecue units, the cooking or food supporting grill is usually suspended directly over a suitable source of heat, such as charcoal or a gas burner with intervening ceramic briquets. The heat source may also be exposed electrical resistance elements as well known in the art. Cooking or barbecue units of these types usually employ rod-type grillwork fabricated from wire rods arranged in parallel and spot welded to a peripheral stringer and one or more cross stringers.
One of the problems encountered with such prior art grills is that they allow practically all of the convective heat which does not come into direct contact with overlying foodstuffs to escape upwardly without transferring significant cooking heat to the food. It is also desirable when barbecuing to leave distinctive sear marks on the foodstuff being cooked, especially meats. The narrow rods of the prior art usually do not become hot enough to actually sear the food material and when such rods can be heated sufficiently, they produce a very narrow sear mark which is not attractive in appearance.
Although cooking grids with inverted U-shaped channels are found in the prior art as illustrated in U.S. Pat. No. 3,369,481 to Pappas, such grids in the past have been fabricated from cast iron. These grids are extremely heavy and easily broken or cracked if inadvertently dropped or subjected to rapid changes in temperature. Both cast iron grids and wire-type grills are relatively expensive to manufacture and quickly become corroded and unsightly in use. Furthermore, these cooking structures are difficult to clean which enhances their unsightly appearance and promotes corrosive action by the retained food drippings.